Studies are being performed with the overall objective of elucidating the mechanisms of water and electrolyte transport in the cornea and determining the role of these mechanisms in the maintenance of corneal transparency. Specifically the work at present is oriented towards a) the determination of the electrical characteristics of the corneal layers, i.e., the epithelium, the stroma and the endothelium, b) the ion selectivities of the various layers of cornea c) determination of the conductances of the limiting membranes of the epithelium and endothelium, and d) determination of the resistance of the layers to the diffusion of ions across them. Bibliographic references: Graves, C. N., S. S. Sanders, R. L. Shoemaker, and W. S. Rehm. Diffusion resistance of endothelium and stroma of bullfrog cornea determined by potential response to K plus. Biophys. J. 15:230a, 1975. Rehm, W. S. Ion transport and short-circuit technique. In: Current Topics in Membranes and Transport, Vol. 7, edited by Felix Bronner and Arnost Kleinzeller, New York and London, Academic Press, pp. 217-270, 1975.